Biographical Movies

Saw Walk the Line weekend before last & was reminded of it by a co-worker. Great show, but like a lot of the recent biographical movies, it STOPS in 1968!? I was left hanging. What about the rest of this guy's life? We're missing out on 35+ years of Cash! I actually met JC in 1974, and have his autograph hangin on my wall. Ray was the same thing. Again great movie, but what about the rest? We get the beginning and the early to mid adulthood, and then the credits roll. Frustrating to say the least.